The GT7864 is designed to provide multi-channel simulation of close-to-ground and close-to-28 VDC signals. The GT7864 is offered in four configurations: A through D, providing 32 output channels (Versions A and B) or 64 output channels (Versions C and D). The GT7864 provides four voltage rails and each of the GT7864's discrete outputs can be pre-defined as to which rail will be used as Hi and which as Lo. Each of the four voltage rail sources can be derived from an on-board DAC or from an External (EXT) input source.

In Versions A and C, the discrete outputs are jumper wired to pre-selected rails, while in Versions B and D, the discrete outputs are software programmable on the fly to any of the four rails.

Architecture:

The GT7864 is equipped with four DACs and four external inputs. Each of the eight signals can be switched to one of four voltage rails. Each of the 32 (or 64) channels can be connected to each of the rails using jumpers (Versions A and C) or relays (Versions B and D).

Version A provides 32 discrete output channels and uses jumpers to pre-configure which rail sources feed which channels. For each channel, there is a choice of Hi Rail and Lo Rail combinations. Version B has 32 channels and uses relays to configure the reference sources. The configuration is controlled by software for maximum flexibility. Version C is identical to Version A, except it provides for 64 channels. Version D is identical to Version B, except it provides 64 channels.

An on-board EEPROM saves system configuration status for query by software and for calibration.

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